change a way to get a block of buffer to get better perf

Author: ginkgoch

index.js

@@ -76,8 +76,7 @@ module.exports = class BufferReader {
         this._checkPositive(length);
         this._checkOffsetInRange(this.offset + length);
 
-        const buffer = Buffer.alloc(length);
-        this.buffer.copy(buffer, 0, this.offset, this.offset + length);
+        const buffer = this.buffer.slice(this.offset, this.offset + length);
         this.offset += length;
         return buffer;
     }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ginkgoch-buffer-reader",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "main": "index.js",
   "homepage": "https://github.com/ginkgoch/node-buffer-reader",
   "scripts": {